diff --git a/lib/api/gitlab.js b/lib/api/gitlab.js
index 2094654479cd4f4172a76b33afa485b2793b520a..8eeb9a1a3d9e49e171e70662e6db76fc8f3500a9 100644
--- a/lib/api/gitlab.js
+++ b/lib/api/gitlab.js
@@ -319,7 +319,7 @@ async function findPr(branchName, prTitle, state = 'all') {
     ) {
       pr = result;
       // GitHub uses number, GitLab uses iid
-      pr.number = pr.id;
+      pr.number = config.apiVersion === 'v3' ? pr.id : pr.iid;
       pr.body = pr.description;
       pr.displayNumber = `Merge Request #${pr.iid}`;
       if (pr.state !== 'opened') {
diff --git a/test/api/gitlab.spec.js b/test/api/gitlab.spec.js
index 581ef8b846a8f65f58769e91cec7810014d6aeec..33691c42b679bb4b5435e408f296b084a4bbd683 100644
--- a/test/api/gitlab.spec.js
+++ b/test/api/gitlab.spec.js
@@ -482,11 +482,11 @@ describe('api/gitlab', () => {
         body: [
           {
             source_branch: 'some-branch',
-            id: 1,
+            iid: 1,
           },
           {
             source_branch: 'some-branch',
-            id: 2,
+            iid: 2,
             title: 'foo',
           },
         ],
@@ -499,11 +499,11 @@ describe('api/gitlab', () => {
         body: [
           {
             source_branch: 'some-branch',
-            id: 1,
+            iid: 1,
           },
           {
             source_branch: 'some-branch',
-            id: 2,
+            iid: 2,
           },
         ],
       });